public class StudentTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Student student = new Student();
		student.name = "bob";
		student.id = 1001;
		student.age = 10;
		student.sex = "female";
		student.phone = "12132424";
		student.doHomework("math");
		Student student2 = new Student();
		student2.id = 1002;
		student2.name = "aa";
		student2.sex = "male";
		student2.phone = "2486895624";
		Student stu3 = student;
		stu3.id = 2001;
		System.out.print(student.id);
		stu3 = null;
		System.out.print(stu3.id);

	}
}
